1. Field of the Invention
The present invention relates generally to devices which suspend and position a microphone.
2. Description of the Prior Art
In the film and broadcasting industries, a microphone is typically mounted on a boom pole located above the person speaking. The quality of reception for most microphones is dependant on the direction of the microphone. Consequently, recording speech requires that the microphone be positioned as close to the speaker as possible and in the proper orientation. The microphone, the boom pole and its operator must be located out of the view of the camera. When a different person speaks or as the speaker moves, the microphone boom operator must be able to rapidly reposition the microphone for optimal reception.
In general, there are two basic types of microphone boom poles. The first type of microphone boom is a production studio boom. The studio has a boom mounted on a support mast extending vertically from a carriage. The microphone is rotatably attached at the end of the boom. The carriage-type boom is large, difficult to move, and only suitable for a studio environment.
The second type is a hand-held boom often referred to as a xe2x80x9cfish polexe2x80x9d boom. The hand-held type boom is held and guided by a single boom operator who positions and orients the fixed microphone mounted at the end of the boom. An advantage of the fish pole design compared to the studio boom is that the fish pole design is the relative ease and speed that a skilled operator can manipulate the microphone locations quickly and easily. Unlike the studio boom design, the boom can be rapidly relocated.
U. S. Pat. No. 4,748,671, discloses a communication headset with a hinge between the microphone and the ear piece, so that the microphone can be adjusted by the user who is, for example, using a telephone. The present invention is intended for motion picture or television production where the producer""s goal is to capture the speaker""s words and image without filling the microphone. The device disclosed in U.S. Pat. No. 4,748,671 is not intended for, and would not be operable for filming and broadcasting applications.
The primary objectives of the present invention are to provide a light weight, audio boom pole which: (1) permits the operator to rapidly and quietly adjust the angle of boom and the microphone in a number of positions, (2) locks the boom at the desired angle so that it is can be easily and quietly operated by a single operator over an extended period of time and (3) may be collapsed for portability. The microphone must be adjustable from a remote, out-of-camera view location and properly oriented to pick up the dialogue without generating any additional sound.
The present invention is a microphone boom assembly capable of articulation around a pivot joint for precise microphone orientation. The microphone boom assembly includes two cylindrical booms connected to each other. Each boom has a hollow interior for receiving the microphone cord. The booms are extended in a telescopic manner such that the boom is long enough for the operator to stand back outside camera range. A handle is attached to the gripping end of the first boom.
A hinged joint assembly connects the first and second booms. The hinge assembly is hollow and includes two halves, one for receiving each boom pole. Each half of the hinge is pivotally connected to the other. The hinge assembly includes a locking mechanism to secure the desired angle between the two booms and to set the orientation of the booms relative to each other.
Each of the two booms include several sections of concentric pipes with diminishing diameters which are slidably fitted into each other to provide the telescoping feature. A tightening collar is affixed to the end of each section of pipes to provide a locking mechanism so that the user can set the length of each boom.
The end of each outside pipe section of the boom has external male straight threading which is received by the female threading of the next section. Each tightening collar has a collet. When the internal female threading of the collar is tightened onto the external male straight threading of the outside pipe, and the tightening collar is compressed the captive collet against the outer surface of the inside pipe securing the ensleeved inside pipe to the outside pipe at the selected boom length.
Each tightening collar has a dimpled outer surface. The dimpled outer surface is shaped and placed to limit the torque in the tightening or clockwise direction and increase grip torque in the loosening or counterclockwise direction, thus preventing over-torquing of the tightening collar.
The locking mechanism of the hinge assembly preferably includes a locking detent pivotally attached within the hollow hinge assembly. Several detent-receiving slots are arrayed on a portion of the hollow hinge assembly to provide a number of predetermined articulated hinge-locking angles. The locking detent is pivotally biased by a spring to engage an individual detent-receiving slot. The hinge assembly is thereby locked into place and the entire microphone boom assembly is set at a predetermined articulated angle. To change the orientation of the two booms relative to each other, the detent is released from its slot, permitting movement of the two booms. The present invention provides a range of articulation and a locking mechanism not previously attainable with the conventional xe2x80x9cfish polexe2x80x9d type booms.